Personal protective equipment-induced systemic hypercapnic hypoxaemia: translational implications for impaired cognitive-clinical functional performance.

BACKGROUND: Personal protective equipment (PPE) adversely affects pulmonary gas exchange and may result in systemic hypercapnic hypoxaemia and headache. This study aimed to determine what extent PPE affects cerebral symptoms, global cerebral blood flow, and cognitive functional performance. METHODS: Higher surgical trainees participated in a randomized, repeated-measures, crossover study, completing 60 min of laparoscopic surgical simulation in both standard operating attire and type 3 PPE. Measurements were collected at baseline and after 60 min of simulation. The primary outcome measure was headache. Headache was examined using the validated visual analogue scale (VAS) and Environmental Symptoms Questionnaire C (ESQ-C), global cerebral blood flow with duplex ultrasonography, and visuospatial and executive gross/fine motor function with grooved peg board (GPB) and laparoscopic bead (LSB) board tasks. RESULTS: Thirty-one higher surgical trainees (20 men, 11 women) completed the study. Compared with standard operating attire, PPE increased headache assessment scores (mean(s.d.) VAS score 3.5(5.6) versus 13.0(3.7), P < 0.001; ESQ-C score 1.3(2.0) versus 5.9(5.1), P < 0.001) and was associated with poorer completion times for GPB-D (61.4(12.0) versus 71.1(12.4) s; P = 0.034) and LSB (192.5(66.9) versus 270.7(135.3) s; P = 0.025) tasks. Wearing PPE increased heart rate (82.5(13.6) versus 93.5(13.0) beats/min; P = 0.022) and skin temperature (36.6(0.4) versus 37.1(0.5)°C; P < 0.001), but decreased peripheral oxygen saturation (97.9(0.8) versus 96.8(1.0) per cent; P < 0.001). Female higher surgical trainees exhibited higher peripheral oxygen saturation across all conditions. No differences were observed in global cerebral blood flow as a function of attire, time or sex. CONCLUSION: Despite no marked changes in global cerebral blood flow, type 3 PPE was associated with increased headache scores and cerebral symptoms (VAS and ESQ-C) alongside impaired executive motor function highlighting the clinical implications of PPE-induced impairment for cognitive-clinical performance.

The Welsh Institute for Minimal Access Therapy colonoscopy suitcase has construct and concurrent validity for colonoscopic polypectomy skills training: a prospective, cross-sectional study.

BACKGROUND: The Welsh Institute for Minimal Access Therapy (WIMAT) colonoscopy suitcase is an ex vivo porcine simulator for polypectomy training. OBJECTIVE: To establish whether this model has construct and concurrent validity. DESIGN: Prospective, cross-sectional study. SETTING: Endoscopic training center. PARTICIPANTS: Twenty novice (N), 20 intermediate (I), 20 advanced (Ad), and 20 expert (E) colonoscopists. INTERVENTION: A simulated polypectomy task aimed at removing 2 polyps; A (simple), B (complex). MAIN OUTCOME MEASUREMENTS: Two accredited colonoscopists, blinded to group allocation, scored performances according to Direct Observation of Polypectomy Skills (DOPyS) assessment parameters. Group performances were compared. Real-life DOPyS scores were correlated to simulator DOPyS results. RESULTS: Median overall DOPyS scores for novices were 1.00 (1.00-1.87) for A and 0.50 (0.00-1.00) for B (A vs B; P < .01). Intermediates scored 2.50 (2.00-2.88) for A and 2.00 (1.13-2.50) for B (A vs B; P = .03). The advanced group scored 3.00 (2.50-3.50) for A and 2.50 (2.00-3.00) for B (A vs B; P = .01). Experts scored 3.00 (3.00-3.88) for A and 3.00 (2.50-3.50) for B (A vs B; P = .47). Intergroup comparisons for A were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P < .01, I vs E; P < .01, and Ad vs E; P = .46. Intergroup comparisons for B were, N vs I; P < .01, N vs Ad; P < .01, N vs E; P < .01, I vs Ad; P = .03, I vs E; P <.01, and Ad vs E; P = .06. There was no difference between real-life DOPyS scores and simulator scores (0.07). LIMITATIONS: The model does not have inbuilt assessment parameters. CONCLUSION: This simulator demonstrates construct and concurrent validity for colon polypectomy training.

Electrostatic precipitation is a novel way of maintaining visual field clarity during laparoscopic surgery: a prospective double-blind randomized controlled pilot study.

BACKGROUND: Ultravision™ is a new device that utilizes electrostatic precipitation to clear surgical smoke. The aim was to evaluate its performance during laparoscopic cholecystectomy. METHODS: Patients undergoing laparoscopic cholecystectomy were randomized into "active (device on)" or "control (device off)." Three operating surgeons scored the percentage effective visibility and three reviewers scored the percentage of the procedure where smoke was present. All assessors also used a 5-point scale (1 = imperceptible/excellent and 5 = very annoying/bad) to rate visual impairment. Secondary outcomes were the number of smoke-related pauses, camera cleaning, and pneumoperitoneum reductions. Mean results are presented with 95% confidence intervals (CI). RESULTS: In 30 patients (active 13, control 17), the effective visibility was 89.2% (83.3-95.0) for active cases and 71.2% (65.7-76.7) for controls. The proportion of the procedure where smoke was present was 41.1% (33.8-48.3) for active cases and 61.5% (49.0-74.1) for controls. Operating surgeons rated the visual impairment as 2.2 (1.7-2.6) for active cases and 3.2 (2.8-3.5) for controls. Reviewers rated the visual impairment as 2.3 (2.0-2.5) for active cases and 3.2 (2.8-3.7) for controls. In the active group, 23% of procedures were paused to allow smoke clearance compared to 94% of control cases. Camera cleaning was not needed in 85% of active procedures and 35% of controls. The pneumoperitoneum was reduced in 0% of active cases and 88% of controls. CONCLUSIONS: Ultravision™ improves visibility during laparoscopic surgery and reduces delays in surgery for smoke clearance and camera cleaning.

Is motion analysis a valid tool for assessing laparoscopic skill?

BACKGROUND: The use of simulation for laparoscopic training has led to the development of objective tools for skills assessment. Motion analysis represents one area of focus. This study was designed to assess the evidence for the use of motion analysis as a valid tool for laparoscopic skills assessment. METHODS: Embase, MEDLINE and PubMed were searched using the following domains: (1) motion analysis, (2) validation and (3) laparoscopy. Studies investigating motion analysis as a tool for assessment of laparoscopic skill in general surgery were included. Common endpoints in motion analysis metrics were compared between studies according to a modified form of the Oxford Centre for Evidence-Based Medicine levels of evidence and recommendation. RESULTS: Thirteen studies were included from 2,039 initial papers. Twelve (92.3 %) reported the construct validity of motion analysis across a range of laparoscopic tasks. Of these 12, 5 (41.7 %) evaluated the ProMIS Augmented Reality Simulator, 3 (25 %) the Imperial College Surgical Assessment Device (ICSAD), 2 (16.7 %) the Hiroshima University Endoscopic Surgical Assessment Device (HUESAD), 1 (8.33 %) the Advanced Dundee Endoscopic Psychomotor Tester (ADEPT) and 1 (8.33 %) the Robotic and Video Motion Analysis Software (ROVIMAS). Face validity was reported by 1 (7.7 %) study each for ADEPT and ICSAD. Concurrent validity was reported by 1 (7.7 %) study each for ADEPT, ICSAD and ProMIS. There was no evidence for predictive validity. CONCLUSIONS: Evidence exists to validate motion analysis for use in laparoscopic skills assessment. Valid parameters are time taken, path length and number of hand movements. Future work should concentrate on the conversion of motion data into competency-based scores for trainee feedback.

Is surgical smoke harmful to theater staff? a systematic review.

BACKGROUND: Smoke is generated by energy-based surgical instruments. The airborne byproducts may have potential health implications. This study aimed to evaluate the properties of surgical smoke and the evidence for the harmful effects to the theater staff. METHODS: Cochrane Database, MEDLINE, PubMed, Embase classic and Embase, and the metaRegister of Controlled Trials were searched for studies reporting the constituents found in the smoke plume created during surgical procedures, the methods used to analyze the smoke, the implications of exposure, and the type of surgical instrument that generated the smoke. Studies were excluded if they were animal based, preclinical experimental work, or opinion-based reports. The common end points were particle size and characteristics, infection risk, malignant spread, and mutagenesis. RESULTS: The inclusion criteria were fulfilled by 20 studies. In terms of particle size, 5 (25%) of the 20 studies showed that diathermy and laser can produce ultrafine particles (UFP) that are respirable in size. With regard to particle characterization, 7 (35%) of the 20 studies demonstrated that a variety of volatile hydrocarbons are present in diathermy-, ultrasonic-, and laser-derived surgical smoke. These are potentially carcinogenic, but no evidence exists to support a cause-effect relationship for those exposed. In terms of infection risk, 6 (30%) of the 20 studies assessed surgical smoke for the presence of viruses, with only 1 study (5%) positively identifying viral DNA in laser-derived smoke. One study (5%) demonstrated bacterial cell culture (Staphylococcus aureus) from a laser plume after surgery. Regarding mutagenesis and malignant spread, one study (5%) reported the mutagenic effect of smoke, and one study (5%) showed the presence of malignant cells in the smoke of a patient undergoing procedures for carcinomatosis. CONCLUSIONS: The potentially carcinogenic components of surgical smoke are sufficiently small to be respirable. Infective and malignant cells are found in the smoke plume, but the full risk of this to the theater staff is unproven. Future work could focus on the long-term consequences of smoke exposure.

Systematic review of validity testing in colonoscopy simulation.

BACKGROUND: Simulation is a useful adjunct to skills-based training. It potentially avoids risk to patients during training and development of basic interventional techniques. This may be of particular relevance in colonoscopy where the learning curve can be long. Several endoscopic devices exist that simulate colonoscopy for training purposes. This study was designed to review the evidence for the validity of these simulators. METHODS: MEDLINE (1947 to present), PubMed, Embase classic + Embase, the metaRegister of Controlled Trials, and the Education Resources Information Center (ERIC) were searched for studies validating colonoscopy simulators. For each study, we recorded the type of simulator used, the tasks assessed, the endpoints reported, and the type of validity measured. Common endpoints between studies were compared, and the evidence was graded. RESULTS: Thirteen studies met the inclusion criteria. Construct validity was reported in five (41.7 %) studies for the Accutouch HT Immersion (cases 1, 3, and 4), four studies (33.3 %) for the GI mentor II (Simbionix) (Modules 1.1, 1.3, 1.7, 2.1, and 5), two studies (16.7 %) for the Olympus Endo Ts-1 2nd Generation, and one study for the Endo X bovine model. Face validity was reported for the Accutouch HT Immersion, the Olympus 2nd Generation, and the KAIST-Ewha. Content validity was reported for the all simulators, excluding the KAIST-Ewha. The only report of criterion validity was for the Endo X bovine model. CONCLUSION: Evidence exists to support the face, content, and construct validity of several virtual reality colonoscopy simulators for specific diagnostic and therapeutic modules with selected endpoints. One study demonstrates content, construct, and criterion validity for an ex vivo animal platform. Further work is needed to demonstrate the criterion validity of all devices.

Development and evaluation of a novel protective device for upper gastrointestinal endoscopy in the COVID-19 pandemic: the EBOX.

BACKGROUND: During the COVID-19 pandemic, aerosol-generating procedures such as upper gastrointestinal endoscopy (UGIE) have been considered high risk. We designed a novel acrylic box (endoscopy box (EBOX)) with the intention of limiting aerosol and droplet spread during such procedures. We evaluated clinical utility, impact on the endoscopy team and also assessed the impact of the EBOX on macroscopic droplet spread from a simulated cough during UGIE. METHODS: Clinical utility was evaluated prospectively via EBOX use on 15 patients undergoing endoscopic retrograde cholangiopancreatography (13) or endoscopic ultrasound (2). Feedback was recorded from the endoscopy team regarding ease of positioning, impact of the EBOX on procedural performance and cleaning. A cough was simulated via explosion of a hyperinflated balloon containing 0.75 mL of ultraviolet disclosing lotion within the oral cavity of a mannequin, with and without the EBOX. Macroscopic spread was then evaluated with a ultraviolet torch. RESULTS: Three endoscopists and the team members found that the EBOX did not hamper the procedure and felt it was a useful adjunct to full personal protective equipment (PPE). Simulated cough without the EBOX identified macroscopic spread up to 2.3 m away from the patient's mouth as well as onto key areas such as the exposed neck of the endoscopist, which is not considered in current PPE guidance. Simulated cough using the EBOX significantly reduced macroscopic spread onto key areas of the healthcare workers. CONCLUSIONS: The EBOX is a valuable adjunct to recommended PPE for UGIE, but still allows these procedures to be performed in the standard manner.

Assessment of technical parameters and skills training to inform a simulation-based training program for semi-automated robotic colonoscopy.

Background and study aims Video-colonoscopy, despite being the gold-standard for diagnosis of colorectal lesions, has limitations including patient discomfort and risk of complications. This study assessed training characteristics and acceptability in operators of a new robotic colonoscope (RC). Materials and methods Participants (n = 9) with varying degrees of skill and background knowledge in colonoscopy performed colonoscopies with a RC on a simulation-based training model. Quantitative procedure-related and qualitative operator-related parameters were recorded. Results Polyp detection rate was highest in the novice group (91.67 %) followed by experts (86.11 %), then equally, trainees and video gamers (79.17 %). Four participants repeated the procedure at a follow-up session. Each participant improved cecal intubation time and had the same or higher polyp detection rate. The potential role for RC was identified for an out-of-hospital environment and as a novel diagnostic tool. Conclusions Results from this pilot suggest that operators at all skill levels found the RC acceptable and potentially useful as a diagnostic tool. Acquisition of skills with RC seems to improve rapidly to a clinically relevant level with simulation-based training.

Assessment of the human epidermis model SkinEthic RHE for in vitro skin corrosion testing of chemicals according to new OECD TG 431.

Based on two successfully completed ECVAM validation studies for in vitro skin corrosion testing of chemicals, the National Co-ordinators of OECD Test Guideline Programme endorsed in 2002 two new test guidelines: TG 430 'Transcutaneous Electrical Resistance assay' and TG 431 'Human Skin Model Test'. To allow all suitable in vitro human reconstructed (dermal or epidermal) models to be used for skin corrosion testing, the OECD TG 431 defines general and functional conditions that the model must meet before it will be routinely used for skin corrosion testing. In addition, the guideline requires correct prediction of 12 reference chemicals and assessment of intra- and inter-laboratory variability. To show that the OECD TG 431 concept works, in 2003 ZEBET tested several chemicals from the ECVAM validation trials on the SkinEthic reconstituted human epidermal (RHE) model. Based on knowledge that reconstructed human skin models perform similarly in toxicological studies, it was decided to adopt the validated EpiDerm skin corrosion test protocol and prediction model to the SkinEthic model. After minor technical changes, classifications were obtained in concordance with those reported for the validated human skin models EPISKIN and EpiDerm. To allow adequate determination of inter-laboratory reproducibility, a blind trial was conducted in three laboratories -- ZEBET (D), Safepharm (UK) and BASF (D), in which the 12 endorsed reference chemicals were tested. Results obtained with the SkinEthic epidermal model were reproducible, both within and between laboratories, and over time. Concordance between the in vitro predictions of skin corrosivity potential obtained with the SkinEthic model and the predictions obtained with the accepted tests of OECD TG 430 and TG 431 was very good. The new test was able to distinguish between corrosive and non-corrosive reference chemicals with an accuracy of 93%.

Can endoscopists accurately self-assess performance during simulated colonoscopic polypectomy? A prospective, cross-sectional study.

BACKGROUND: The aim of this study was to establish if endoscopists can reliably self-assess their ability to perform simulated colonic polypectomy. METHODS: Novices, intermediates, advanced, and experts performed a video-recorded polypectomy task using the Welsh Institute for Minimal Access Therapy (WIMAT) colonoscopy suitcase simulator. This involved removal of a simple polyp (A) and a complex polyp (B). Participants self-assessed themselves using a Direct Observation of Polypectomy Skills (DOPyS) assessment form. Two blinded, independent, Joint Advisory Group on Gastrointestinal Endoscopy (JAG) accredited assessors graded each performance using the same DOPyS scoring. The Spearman coefficient was used to determine the correlation between self and assessors' scores. RESULTS: Eighty participants completed the task. There was a weak correlation between assessors' scores and self-assessment scores for all groups (novices: ρ = -.44, P = .85; intermediates: ρ = -.16, P = .51; advanced: ρ = .16, P = .50; and experts: ρ = .07, P = .76). There was a strong correlation between scores from assessor 1 and 2 for polyp A (ρ = .80, P ≤ .01) and polyp B (ρ = .80, P ≤ .01). CONCLUSIONS: The correlation between self-assessment and assessors' scores is weak. Novices and intermediates underestimate performance, whereas advanced and experts overestimate performance. Regular feedback may improve accuracy.

An evaluation of a cultured human corneal epithelial tissue model for the determination of the ocular irritation potential of pharmaceutical process materials.

Irritation and other forms of local toxicity following contact with eyes is a potentially serious problem arising from occupational exposure to chemicals. Traditionally, evaluation of the irritant potential of novel chemicals has relied on the use of in vivo studies with rabbits. Concerns about the predictive potential of in vivo methods for human hazard and demand for economical and rapid screening of chemicals has stimulated a great deal of work to investigate in vitro alternatives for evaluating ocular irritation potential. This publication describes a screening study to assess a reconstituted corneal epithelial culture system, as an alternative for testing for ocular irritation with pharmaceutical process materials, extending the chemical domain with which this system has been tested. A total of 21 test chemicals were applied to commercially supplied reconstituted human corneal epithelial (HCE) cultures and effects on tissue viability (MTT reduction assay), tissue histology and IL-alpha expression were assessed. Positive controls (0.5% and 1% SDS) showed dose- and time-related adverse effects on tissues, consistent with known irritant effects. Negative controls showed no histological changes and retained high viability throughout the time-course of the experiment. Concordance was excellent with accuracy at each sampling time point of over 80% when viability (MTT reduction) was compared with existing EU classification of the test articles for ocular irritation (classification based on results of in vivo evaluation). Tissue viability as estimated by MTT reduction appears most useful as the primary means of assessing the irritation potential of the chemicals. Histopathological examination generally agreed with the results of the MTT assay. However, the use of cytokine analysis will need further consideration as results for this parameter showed no relationship with known irritation potential. These results infer that HCE cultures, alone or as a part of a tiered hazard screening programme, have promise for use in reducing reliance on live subject tests and contribute to generation of an appropriate hazard classification and label advice.